NASA and the Apollo astronauts who walked on the Moon have stated that one of the foremost problems to be solved before we return to the Moon concerns lunar dust. This fine (e.g., less than 20 microns) portion of the lunar soil makes up about 20 wt % of the total soil and is extremely clinging, abrasive, toxic and omnipresent. Many activities on the Moon are negatively affected by this dust. During the Apollo missions, it caused reduced movement in the joints of the astronauts' space suits and wore through layers of the Kevlar cloth of the suits. Its clinging nature caused the initially white suits to become dirty, thereby absorbing more black-body heat with each Moon walk. In the lunar module when the astronauts removed their helmets, they experienced distressing sensations from the dust in their eyes, noses, and throats. Equipment having moving parts and friction bearing surfaces exposed to the lunar dust may also be negatively affected. For example, it was found that boxes used to collect and return lunar samples to Earth were not tightly sealed due to the presence of lunar dust. In fact, all Apollo rock boxes leaked, most all the way from 10−12 torr to one atmosphere of Earth air.
It would be desirable to mitigate such dust problems by converting the dust into roadways or other useful construction materials. In so doing, the amount of dust that the various activities on the Moon would normally generate would be held to a minimum.